Selective Nuclear Lithiation of Aromatic Compounds: Facile Synthesis of Methoxyphthalide Derivatives by Carboxylation of the Lithio-Compounds

The aromatic compounds, which have both hydroxymethyl and methoxyl groups at 1,3-position, were lithiated mostly at 2-position with n-butyllithium. This reaction would provide a useful synthetic method of methoxyphthalide derivatives, in conjunction with carboxylation of the resulting lithio-compounds.